Office chair



1.1 is a front elevation view of the office chair showing my new invention;

1.2 is a rear elevation view thereof;

1.3 is a left side elevation view thereof;

1.4 is a right side elevation view thereof;

1.5 is a top elevation view thereof;

1.6 is a bottom elevation view thereof;

1.7 is a front perspective view thereof; and

1.8 is a rear perspective view thereof.

The broken lines represent environmental structure, and form no part of the claimed design. 

CLAIM The ornamental design for an office chair, as shown and described. 